Method of and means for recovering products from fractionating condensers



Aug. 20, 1929. L. w. SNELL W METHOD OF AND MEANS FOR RECOVERING PRODUCTS FROM FRACT I ONAT I NG CONDENSERS Filegl A 23. 1926 2 Sheets-Shet COOLER M TOP/YE K9 Patented Aug. 20, 192 9 UNITED STATES- mm OFFICE.

LESTER W. SNELL, OF WOOD RIVER, ILIIHOIS.

Application filed August 28, 1926. Serial 10 181912.

This invention relates to methods of and "means for recovering products from fractionating condensers, and especially to the recovery of products in the distillation of 5 petroleum h dro-carbons and similar oils consistin 0 various fractions having different boiling points.

TIn the ordinary fractionating condenser, vapors are gradually cooled in rising from a lo vapor inlet at the bottom to a vapor outlet at the to and the relatively cool condensate falling om the upper portions of the condenser serves as a cooling medium for the lower portions. If all of this relatively cool condensate were immediately removed, without being permitted to drop to the hotter zones, the ordinary fractionating condenser would become extremely hot, especially at its lowerportion, and in addition to the danger of overheating there would be an objectionable temperature condition tending to prevent the desired fractional condensation. v One of the objects of the present invention is to withdraw relatively large quantities of the condensate withoutincurring the danger and other disadvantages of overheating. Briefly stated, this object is accomplished by a cooling operation which compensates, for the removal of the con-' densate. In the preferred form of the invention, the condensate is withdrawn from the system as a product, (and a portion of this product is cooled and then returned to the fractionating condenser.'

A further object is to recover from a fractionating condenser a roduct havin a predetermined initial boi ing point an a predetermined end point. I will hereafter de- 40 scribe the manner in which a fractionating condenser may be divided into difierent zones, with a predetermined temperature at each end ofeach zone, so as to provide for the discharge of finished products from each zone. Large quantities of each product can be removed from each zone, without overheating or otherwise disturbing the functions of the fractionating condenser. Particular attention is directed to the importance of accurately predetermining the initial and end point of each product, so as CONDENSEBB.

the top. The fraction having the BEISSUED tained at a predetermined temperature by cooling and returning ortionsof the condensate. The return of the cooled condensate may be regulated automatically b means of thermostats at the ends of eac zone. The initial and end point of each fraction is therefore very accurately determined, and the co6led condensate maintains the desired tem rature conditions without liability of over eating.

- In the preferred form of the invention, -I obtain predetermined finished products from each zone, and I preferably introduce 7 steam into each zone to remove light fractions that would unduly lower the flash point. x Fig. I is a dia ammatical view of an apparatus embodying the features of this invention.

Fig. II is a vertical section on a larger a scale showingthe fractionating condenser, the middle portion of the condenser being broken away.

-Fi III is a horizontal section through the actionating condensen' Fig. IV is a section on the curved line IVIV Fig. III showing two of the small vapor pipes and an dverflow pipe.

7 1 designates an ordinary pipe still,- or tube still, having a-discharge pipe 2 connected to the lower end rtion of a fractionating wndenser'A. estill may be. heated in any suitable manner, and any desired means may be employed to force the charlgznthrough the still, for the invention is not 'ted to a still of any particular type.

The fractionating condenser which I have shown to illustrate tlfe invention is the form of a vertical tower exposed to the air. A vapor pipe 3 leads from'the top of this towelto a final condenser '4. The hot vapors entering through pipe 2, at the bottom of the fractionating condenser, are gradually cooled in rising toward the vapor piple "abe intermediate fractions are condensed be tween the top and bottom of the fraction-- ating condenser.

Numerous partitions 5 are located in the fractionating condenser, and eachof'these partitions is provided with a series of" vapor pipes 6 through which the vapors rise from one partition to another. As shown by Fig. III, the vapor pipes 6 are arranged in curved rows at opposite sides of the fractionating condenser, so'the vapors passing from one group of pipes 6 willflow, horizontally tothe other side of the condenser before entering the next higher group of pipes.

Each partition 5 I overflow pipe 7 through which condensate drops to the next lowerpartition. The upperportion of each overflow pipe 7 lies in a chamber 8 having a flange 9 which extends into the adjacent pool of condensate,

as shown in Fig. IV, toprovide a liquid seal around the overflow pipe. A curved strip of metal 10 (Fig.-III) extends from each chamber 8 to form a passageway through which condensate flows to the chamber, and a group of the vapor pipes 6 lies in this passageway.

Each vapor pipe 6 has small openings in its lower end (Fig. IV), but the condensate tending to escape through these openings is thrown upwardly by the rising vapors. The relatively cool condensate is thus brought into intimate contact with the vapors.

The several zones in the fractionating condenser are provided with separate discharge pipes 12, 13, 14 and 15, through which predetermined products are withdrawn. In the zone at the lower end of this condenser, the product having the highest boiling points is condensed and then discharged through pipe 12 to a storage tank 12. The several zones are separated from each other by means of partitions 16 (Fig. II) and each of these partitions-is provided with a large central vapor passage 17 through which the vapors rise from one zoneto another. Each of the discharge pipes 13, 14 and 15 leads from a partition 16 at the bottom of a zone to receive theliquid product condensed in that zone.

To provide for the cooling and return of portions of these products, coolers 18 may be connected to the pipes 13, 14 and 15, respectively, and each cooler may be provided with an outlet pipe 19 having a branch 20 through which cooled condensate is returned to the condenser, and a branch 21 through which the product is conducted to a storage tank.

also provided with an Fig. I shows how the product discharged through pipe 13 is transmitted through a cooler 18 and pipes 19 and 21 to a storage tank 13'. In like manner, the products discharged through pipes 14 and 15 are transmitted to tanks 11 and 15', respectively,

while the product from the final condenser 4 is conducted through pipe 22 to a tank 23.

-To-- maintain predetermined temperatures in diflerent portions of the fractionatlng condenser, the return of the cooled condensate may be regulated by adjusting valves 24' in the return pipes 20. As shown by Fig. II, each cooler 18.1"eceives condensate from the top of a partitionl6 which forms the bottom of one zone, and regulated quantities of the cooled condensate are transmitted through a valve 2et'to the upper portion of the next lower zone. By suitably regulating the return ofthe cooled condensate, predetermined temperatures can be maintained at each end of each zone, thereby providing for the discharge of a predetermined product from each zone, and at the same time preventing overheating of the condenser. The cooling and return of portions of the products compensates forthe removal of large quantities of condensate which ordinarily aids in the cooling of alfractionating condenser.

I have referred to predetermined temperatures at each end of several zones, but it will be understood that the lower end of the .bottom zone does not require temperature *regulat1on,;for the residual product is discharged at this point. However, thetop of p the highest zone is preferably provided with a cooler 18 receiving condensate from a pipe .25 connected to the air-cooled vapor pipe 3.

The'cool condensate is discharged from this cooler through a pipe 19 having a branch 20 leading into the top of the condenser, and a branch 26 through which the excess is discharged. The pipe 19 just referred to is provided witha regulating valve 24.

The several valves 24, which control the return of cooled condensate, are preferably adjusted automatically by means of thermostats 27 located inside of the condenser and provided with operating rods 28 connected to said valves, as shown in Fig. II. A predetermined temperature is thus maintained at each end of each condensing zone, with the exception of the'lower end of the bottom zone.

Owing to the importance of obtaining predetermined finished products from each zone, I preferably introduce steam through pipes 29 leading to the lower end of each zone, so as to remove the light fractions that understood that under some conditions condensate should be permitted to drop from ing point may be delivered to tank 12', while the intermediate roducts may be 37 to 40 B. distillate in tank 13, kerosene in tank 14;" and naphtha in tank 15'.

While I have emphasized the importance of cooling the fractionating condenser to compensate for the withdrawal of relatively cool condensate, it is to be understoodthat the word compensate does not refer to an exact equivalent of the ordinary cooling.

The preferred form of the invention includes the regulation of the temperatures at the ends of the condensin zones and this involves a departure from t e ordinary coolin but the additional artificial cooling provi es for the withdrawal of large quant ties of each roduct without overheating any of the con ensing zones. I claim:

1. In the art of distillilg hydrocarbons,

the method of obtaining ctional liquid products having cpredetermined initial and end ints, whi comprises withdrawing fractional liquid products from condensing zonesin a fractionating condenser, maintaining predetermined vapor temperatures at each end of one of said zones by cooling said withdrawn liquid products, discharging portions of one of said cooled liquid products into the vapors entering the last mentioned zone, discharging portions of another of said cooled liquid products into the vapors leav ing said last mentioned zone, and varying the flow of said portions in response to-variations in the temperature of the vapors into which the I are discharged, so as to predetermine t e initial and end point of the product condensed in said lastvmentioned zone, and separately recoverin the remaining portions of said with rawn liquid roducts.

2. In the art of distillin the method of obtaining ractional liquid products having redetermined initial and end points, whic comprises withdrawing said fractional liquid products in separate streams from different zones in a frachonat ing condenser, maintaining predetermined vapor temperatures at each end of each of said zones-by cooling said withdrawn liquid products, delivering portions :of the cooled products into the vapors at the respective. the vapors so as to cool ends of said zones hydrocarbons,

entering and leavi flow of each of sai portions in response to variations in the temperature of the vapors termine the initial and end point of each of said fractional products, and'separately recoverin the remaining rtions of ,said withdrawn fractional pro ucts.

3. In the art of distilling hydrocarbons the method ,of obtaining fractional liquid products having predetermined initial and end points, which comprises maintaining ls of liquid in fractional condensing zones in a fractlonating condenser, bubbling h drocarbon vapors through said pools, wit drawing fractional liquid products inseparate streams from the lower ends of the said zones, varying the ;into which it is discharged, so as to prederespective zones, maintaining predetermined vapor temperatures at each end of each of saidzones by cooling said withdrawn liquid products, delivering port-ions of the cooled products into the vapors at the respective ends of said zones so as to cool the vapors entering and leavin said zones, varying the flow of each of said portions in response to variations in the temperature of the vapors into which it is discharged, so as to predetermine the initial and end point of each of said fractional products, and separately recovering the remainingrtions of said withdrawn fractional prociiibts.

4. In the art of distilling hydrocarbons, the method of.obtaining fractional liquid products having lpredetermined initial and end points, WhlC comprises maintaining pools of liquid in zones in a fractionating condenser, bubbling hydrocarbon vapors through said pools, also bubblin steam through said pools to remove light ractions therefrom, withdrawing fractional liquid products in separate streams from the lower ends of the maintaining predetermined vapor temperatures at each end of each of said zones by cooling said withdrawn liquid products, delivering portions of-the cooled products into the vapors at the respective ends of said zones so as to cool the vapors enterin and leaving said zones, varying the flow 0 each of an portions in response to variations in the temperature of the vapors into which it s dischar so as to predetermine the initial an tional products, and sepa'ratel the remaining portions'of fractional products.

'5. fractionat' condenser having a plu ralrtvof condensing chambers, means for mamtammg predetermined temperatures at the top and bottom of each of said chambers to determine the initial boiling point and endpoint of the product condensed in chamber, said means including cooling devices receivlng condensate from the respecrecovering withdrawn tiv'e chambers in said condenser, return con ,fractional condensing respective zones,

end point of each ofsaid fraccondensate are conducted from said cooling devices to said condenser, said return conductors being in communication with said condenser at points near the ends of said chambers and thermostats in said condenser near said ends of the chambers regulating the flow through said return conductors, and q delivery pipes whereby the predetermined ,products are separately discharged from said 10 cooling devices.

In testimony that I claim the foregoing I hereunto-affix my signature.

LESTER W. SNELL. 

